ARM: DaVinci: Add DaVinci CPU identification code.

- Patch adds DaVinci CPU identification based on DEVICE_ID
  register.
Signed-off-by: Komal Shah <komal_shah802003@yahoo.com>

arch/arm/mach-davinci/Makefile

@@ -5,8 +5,8 @@
 
 
 # Common objects
-obj-y 				:= time.o irq.o dma.o clock.o serial.o io.o \
-					devices.o gpio.o
+obj-y 			:= time.o irq.o dma.o clock.o serial.o io.o \
+			devices.o gpio.o id.o
 
 # Board specific
 obj-$(CONFIG_MACH_DAVINCI_EVM)  	+= board-evm.o i2c-emac.o

arch/arm/mach-davinci/id.c

+/*
+ * linux/arch/arm/mach-davinci/id.c
+ *
+ * Davinci CPU identification code
+ *
+ * Copyright (C) 2006 Komal Shah <komal_shah802003@yahoo.com>
+ *
+ * Derived from OMAP1 CPU identification code.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+
+#define DAVINCI_DEV_ID		0x01c40028
+
+struct davinci_id {
+	u16	jtag_id;	/* Device Part No. (Unique JTAG id)*/
+	u8	dev_rev;	/* Processor revision */
+	u32	mfg_jtag_id;	/* Manufacturer JTAP id */
+	u32	type;		/* Cpu id bits [31:08], cpu class bits [07:00] */
+};
+
+/* Register values to detect the DaVinci version */
+static struct davinci_id davinci_ids[] __initdata = {
+	{ .jtag_id = 0xb700, .dev_rev = 0x2, .mfg_jtag_id = 0x017, .type = 0x64430000},
+};
+
+/*
+ * Get Device Part No. from DEV_ID.
+ */
+static u16 __init davinci_get_jtag_id(void)
+{
+	u32 dev_id, jtag_id;
+
+	dev_id = davinci_readl(DAVINCI_DEV_ID);
+
+	jtag_id = ((dev_id >> 12) & 0xffff);
+
+	return jtag_id;
+}
+
+/*
+ * Get Device Revision from DEV_ID.
+ */
+static u8 __init davinci_get_dev_rev(void)
+{
+	u32 dev_rev;
+
+	dev_rev = davinci_readl(DAVINCI_DEV_ID);
+
+	dev_rev = (dev_rev >> 28) & 0xf;
+
+	return dev_rev;
+}
+
+void __init davinci_check_revision(void)
+{
+	int i;
+	u16 jtag_id;
+	u8 dev_rev;
+
+	jtag_id = davinci_get_jtag_id();
+	dev_rev = davinci_get_dev_rev();
+
+#ifdef DEBUG
+	printk("JTAG_ID: 0x%04x DEV_REV: %i\n", jtag_id, dev_rev);
+#endif
+
+	/* First check only the major version in a safe way */
+	for (i = 0; i < ARRAY_SIZE(davinci_ids); i++) {
+		if (jtag_id == (davinci_ids[i].jtag_id)) {
+			system_rev = davinci_ids[i].type;
+			break;
+		}
+	}
+
+	/* Check if we can find the dev revision */
+	for (i = 0; i < ARRAY_SIZE(davinci_ids); i++) {
+		if (jtag_id == davinci_ids[i].jtag_id &&
+		    dev_rev == davinci_ids[i].dev_rev) {
+			system_rev = davinci_ids[i].type;
+			break;
+		}
+	}
+
+	printk("DM%04x\n", system_rev >> 16);
+}
+

arch/arm/mach-davinci/io.c

@@ -14,12 +14,15 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 
+#include <asm/tlb.h>
 #include <asm/io.h>
 
 #include <asm/mach/map.h>
 #include <asm/arch/memory.h>
 
 extern int davinci_clk_init(void);
+extern void davinci_check_revision(void);
+
 /*
  * The machine specific code may provide the extra mapping besides the
  * default mapping provided here.
@@ -42,6 +45,18 @@ static struct map_desc davinci_io_desc[] __initdata = {
 void __init davinci_map_common_io(void)
 {
 	iotable_init(davinci_io_desc, ARRAY_SIZE(davinci_io_desc));
+
+	/* Normally devicemaps_init() would flush caches and tlb after
+	 * mdesc->map_io(), but we must also do it here because of the CPU
+	 * revision check below.
+	 */
+	local_flush_tlb_all();
+	flush_cache_all();
+
+	/* We want to check CPU revision early for cpu_is_omapxxxx() macros.
+	 * IO space mapping must be initialized before we can do that.
+	 */
+	davinci_check_revision();
 }
 
 void __init davinci_init_common_hw(void)